In a battery, such as, e.g., a lithium ion secondary battery, it is becoming more likely to be required to be colored to unify its color with the outer appearance of a device such as an electric apparatus to which the battery is mounted. To provide a solid feeling and a sense of quality, devices are likely to be colored black. In such cases, batteries are becoming more likely to be colored in black. It is also becoming increasingly more likely to be colored in other various colors.
In order to color the battery in black, etc., there are means such as coloring the resin layer constituting the battery packaging material, proving a print layer under the base resin layer, etc.
For example, as a packaging material for batteries having a colored layer, a packaging material having a structure in which a base layer, an adhesive agent layer, a metal foil layer, and a heat adhesive resin layer are laminated in this order, and a pigment is added to any one of the layers among the base layer, the adhesive agent layer, and the metal foil layer (see Patent Document 1), an outer packaging material for batteries having a layer containing a blackbody material such as a carbon material, etc. (see Patent Document 2), and a structure in which a white resin film base material is laminated on a surface of a battery outer packaging material and a white ink layer is laminated on the surface of the white resin film base material (see Patent Document 3), are known.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2011-054563
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2011-096552
Patent Document 3: Japanese Unexamined Patent Application Publication No. 2009-289533